Smoking is harmful to health. At present, all countries of the world are vigorously promoting tobacco-free campaigns. Electronic cigarette, also called simulating cigarette, has the same appearance as conventional cigarettes and the similar flavor to conventional cigarettes, even has much more flavors than conventional cigarettes. The electronic cigarette also can create aerosols, flavors and a feeling of smoking, like conventional cigarettes. However, the electronic cigarette has no harmful ingredients such as tar and particulate matter existing in conventional cigarettes, and forms no second hand smoke filling in air. The electronic cigarette can effectively eliminate the harmful substances produced during conventional smoking, and can give a feeling of smell the same as conventional smoking to users. Therefore, the electronic cigarette is mainly used for quitting smoking and substituting conventional cigarettes, and it plays a great role in the promotion of tobacco-free campaigns. Current electronic cigarettes mainly include an atomizer and a battery box. The battery box has a big button thereon. The big button generally is complex in structure and tedious to assemble. The assembly of many parts inside the big button occupies a large space and the electronic cigarette is inconvenient to carry. Moreover, the big button often is stuck, oblique, shaky, etc., resulting in uneven strength or failure of the big button. Consequently, the button has a short service life.